Historical analysis to identify malicious activity

ABSTRACT

Systems and methods may use historical analysis to identify malicious activity. A discovery/recovery system may comprise a processor in communication with a network and in communication with a database. The discovery/recovery system may gather filtered historical network data associated with an asset associated with the network. The discovery/recovery system may analyze the filtered historical network data to determine whether a subset of the filtered historical network data is associated with a malware infection of the asset.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and derives the benefit of the filing date of U.S. Provisional Patent Application No. 61/696,013, filed Aug. 31, 2012. The entire content of this application is herein incorporated by reference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a network according to an embodiment of the invention.

FIG. 2 depicts a monitoring process according to an embodiment of the invention.

FIG. 3A depicts an analysis system according to an embodiment of the invention.

FIG. 3B depicts an analysis system according to an embodiment of the invention.

FIG. 4 depicts an analysis process according to an embodiment of the invention.

FIG. 5 depicts a real time analysis process according to an embodiment of the invention.

FIG. 6 depicts an historical analysis process according to an embodiment of the invention.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

Methods and systems described herein may detect malicious activity, for example malicious activity within computer networks, present users with evidence in order to confirm an identification of infection, and/or annotate a detection with information which may explain some or all of the infection cycle allowing users to revisit their security policies and/or understand the severity of the infection. Identification, capture, index, and/or examination of network summary information, including network summary information which might contribute to a detection or understanding of a threat, may be performed. Historical, present, and/or future network events may be compared to simulated data in order to discover effects and/or implications of malicious activity. Historical, present, and/or future network data may be re-examined, captured, and/or indexed to discover precursors to malicious activity, present malicious activity, and/or future malicious activity. Discovery and/or recovery of historical infector malware may be performed based on future network communications. The probability of maliciousness in network traffic patterns and/or the degree of automation within suspicious network activity may be determined.

Devices operating the various applications and performing the various processes described herein may comprise one or more computers. Computers may be linked to one another via a network or networks. A computer may be any programmable machine capable of performing arithmetic and/or logical operations. In some embodiments, computers may comprise processors, memories, data storage devices, and/or other commonly known or novel components. These components may be connected physically or through network or wireless links. Computers may also comprise software which may direct the operations of the aforementioned components. Computers may be referred to with terms that are commonly used by those of ordinary skill in the relevant arts, such as servers, PCs, mobile devices, and other terms. It will be understood by those of ordinary skill that those terms used herein are interchangeable, and any computer capable of performing the described functions may be used. For example, though the term “server” may appear in the following specification, the disclosed embodiments are not limited to servers. A network may be any plurality of completely or partially interconnected computers wherein some or all of the computers are able to communicate with one another. It will be understood by those of ordinary skill that connections between computers may be wired in some cases (i.e. via Ethernet, coaxial, optical, or other wired connection) or may be wireless (i.e. via WiFi, WiMax, or other wireless connection). Connections between computers may use any protocols, including connection oriented protocols such as TCP or connectionless protocols such as UDP. Any connection through which at least two computers may exchange data can be the basis of a network.

FIG. 1 depicts a network 100 according to an embodiment of the invention. The network 100 may be, for example, an internal network such as a business network, home network, educational network, or the like. The network 100 may include assets 110 such as computers, switches, routers, other networked devices, and/or other infrastructure to support internal and external network communications. Each asset 110 may be an individual endpoint (111, 112, . . . n) within the network 100. The network 100 may also include infrastructure 130 for facilitating external network communication, for example firewalls, proxy servers, DNS servers, routers, and/or switches. This infrastructure 130 may enable network traffic 120 to flow to and from external networks 150 such as the Internet or a private network. One or more computer systems 140 for identifying malicious network activity may also be included in the network 100. As will be described in greater detail below, these systems 140 may have deep packet inspection, packet reassembly, and/or traffic analysis capabilities for monitoring assets 110 and traffic 120. These systems 140 may identify and capture/index network summary information which might contribute to an increased detection or understanding of a threat: By storing summary attributes of certain network events, it may be possible to both efficiently capture/index attributes as well as search and correlate this data. The network 100 of FIG. 1 may be a typical network description, but the systems and methods described herein are not limited to any specific network topology, network traffic, or destinations residing on the Internet. For example external networks 150 may include a private network, infrastructure 130 may represent varying combinations of network infrastructure and different topologies, and the network 100 may be a service provider network, an MPLS WAN network, or a higher-ed (EDU) network.

Capture and Index of Network Information

FIG. 2 depicts a monitoring process 200 according to an embodiment of the invention. This example process 200 may be performed by the computer systems 140 of FIG. 1. Network traffic 120 may be monitored 210. Monitoring 210 may include, but is not limited to, monitoring the traffic's 120 transport protocol 211, application protocol 212, destination and/or source 213, and/or content 214. Monitoring 210 may include storing data for further analysis. The monitored data may be assessed 220. Assessment 220 may be based on, but is not limited to, the destination and/or source 221 and content 222 of the monitored traffic. Based on the assessment 220, suspicious traffic may be identified 230. A determination of suspicion may be based on, for example, a low reputation score with respect to the destination of the network traffic; activity and files related to suspicious domain generation algorithm (DGA) clusters; and/or suspicious content such as files, headers, HTTP traffic, scripts, etc.

Many different techniques may be used to help determine traffic suspicion. For example, suspicion may be based on a low traffic destination reputation score. One or more databases may contain known malicious or legitimate domain reputations for the destination domain of a communication attempt. Also, reputations may be determined for unknown domains, for example by receiving passive DNS query information, utilizing the DNS query information to measure statistical features of known malicious and legitimate domain names, and utilizing the statistical features to determine a reputation of a new domain (for example, likely malicious or likely legitimate). For more information on systems and methods for determining suspicion based on a low reputation score, see U.S. Patent Application Publication 2012/0042381, “Method and System for Determining Whether Domain Names Are Legitimate or Malicious,” the entirety of which is incorporated by reference herein.

Suspicion may also be based on communications with unregistered domains and/or domains generated by domain generation algorithms. For example, NX domains (NXs) may be domains not registered with authoritative domain name servers. Malware may use NXs to facilitate communication between network assets and external criminal networks. Detecting suspicious activity surrounding NXs may be done by collecting NX domain names from an asset, using these NX domain names to create testing vectors, classifying the testing vectors as benign vectors or malicious vectors based on training vectors, and classifying the asset as infected if the NX testing vector created from the collected NX is classified as a malicious vector. Other NX testing methods may be possible. NX domains may be generated by DGA clusters. Malware on an asset may use DGA to contact external criminal networks. In one example, detecting infections by malware using DGA may be done by clustering randomly generated NX domains that may have been generated by a DGA based on common characteristics, determining which clustered randomly generated domains are correlated in network usage and time, and using this data to determine the DGA that generated the clustered randomly generated domain names. For more information on systems and methods for determining suspicion based on activities and files related to suspicious DGA clusters, see U.S. Patent Application Publication 2011/0167495, “Method and System for Detecting Malware” the entirety of which is incorporated by reference herein.

Both well-known techniques such as both static and dynamic file analysis, header anomalies, and script analysis as well as novel or unknown techniques may be employed as methods and procedures for determining suspicion based on content. For examples of other malware detection techniques which may be applicable to the systems and methods described herein, see U.S. Patent Application Publication 2012/0143650, “Method and System of Assessing and Managing Risk Associated with Compromised Network Assets,” the entirety of which is incorporated by reference herein. Those of ordinary skill in the art will appreciate that other tests and criteria for suspicious activity may be possible.

If the activity is not regarded as suspicious, it may be disregarded 250. If the activity is regarded as suspicious, then metadata associated with the activity may be captured and indexed 240. This may be done using well known techniques in some embodiments. Examples of metadata that may be associated with the activity may include, but are not limited to:

Destination Inspection

Port (Source/Destination)

Transport Protocol (TCP/UDP)

Application Protocol (DNS, HTTP, FTP, SMTP, SMB, IRC, etc.)

Time stamp and/or duration

Source IP, MAC, hostname

Destination IP/Domain

Bytes in/Bytes out

Success/Status of the connection

DNS RR Set

For HTTP requests

Host, Referrer, URI, Verb, User Agent, etc.

For HTTP response

Server, Cache, Content Encoding, Content Type, etc.

For Content

File or Content Itself

Subsequent Communications over period of time

Data that is captured and indexed may provide forensic information surrounding infections on assets 110 within the network 100 and may serve as the base activity for other methods and systems presented below.

Simulated Traffic Comparison

Once suspicious activity is identified, historical, present, and/or future network events may be compared to simulated data in order to discover the effects and implications of malicious activity: Simulated traffic comparison may be performed to prove that malware actually ran on an asset 110 in question and/or to explain the lifecycle of the infection. Proving that the malware ran may involve matching actual network data related to the asset 110, collected utilizing the methods described above with respect to FIG. 2 for example, against destination data contained in simulated data generated by a malware analysis engine. For example, if specific destination data traits (for example, destinations, paths, patterns, and behaviors) are observed in both simulated data and actual data from assets 110, then those traits may become strong indicators of compromise, as the similarity of the temporal occurrence and the uniqueness of the traits may be statistically relevant. Having proof of malware running on an internal asset 110 may allow a system to reduce a false positive rate, may remove conviction uncertainty on the part of a network user or administrator, and may help a network user or administrator to understand the severity of the infection inclusive of but not limited to the systems and methods described in U.S. 2012/0143650. Other examples may include correlation with other customer security product events such as proxy block pages, resulting connections to sinkholed destinations, determination that the infection has disabled host based protection via registry key changes, etc. Explaining the infection lifecycle may include matching the buffered data against data associated with research intelligence systems that may perform reputation, content, and behavioral analysis to determine a type of criminal destination (infector, updater, data drop, etc.) inclusive of but not limited to the systems and methods described in U.S. 2012/0042381, as well as other proprietary systems that identify C&C destinations, DGA activity, or clusters of malware, for example. Based on this analysis, an annotation of criminal destination type in the user interface may allow for accurate severity scoring inclusive of but not limited to the systems and methods described in U.S. 2012/0143650. Other examples may include correlation with other customer security product events such as proxy block pages, resulting connections to sinkholed destinations, determination that the infection has disabled host based protection via registry key changes, etc. Such annotation may help a user to understand the severity of the infection, may allow the system to identify how much data has been exfiltrated, may allow understanding of malware update frequency, may allow the use of host-based software, which may include well-known third party software, to retrieve malware updates that were encrypted payloads over the network, and may allow a determination of the infection profile (low and slow, password stealer, spammer, infecting other internal assets, etc).

FIGS. 3A-3B depict an analysis system 320 according to an embodiment of the invention. This example system 320 is presented in the context of an example flow of an infection lifecycle with an infection vector wherein malware 310 from an external network 300 may enter an internal network 330 and may be delivered to an endpoint asset 331. If the malware 310 successfully infects the endpoint 331, then the malware 310 may install 332 and communicate 333 to a cyber-criminal infrastructure 350 to get updated 351. After an update 351, the malware 310 may download a new malware sample with a downloader 354 and may be updated/customized to new malware 334. The new malware 334 may then communicate 335 to the cyber-criminal infrastructure 350. The communication 335 may include criminal communication such as delivering stolen data to a repository 352, receiving new instructions via command and control (C&C) portals 353, and/or other communication types 355.

During an initial transit of malware 310 from an external network 300 to the internal network 330, the system 320 may watch the malware 310 in motion and may make a copy of the malware 315 for analysis. The copy of the malware 315 may be delivered to a dynamic analysis sub-system 340, which may perform both static and dynamic analysis on the malware 315. The malware 315 may be loaded into the simulated endpoint 341, where the malware 315 may follow a similar infection lifecycle as did malware 310 on endpoint 331. In this example, malware may install 342, communicate 343 to the cyber criminal infrastructure 350, and/or be updated and customized 344. New malware may communicate 345 to the cyber criminal infrastructure 350.

The system 320 may include an asset monitoring subsystem 140 (described with reference to FIG. 2 above), which may capture and index the selective network communications metadata of the potentially infected asset 331. The system 320 may also include a simulation monitoring subsystem 370, which may capture and index the simulated network communication activity from sub-system 340. The simulation monitoring subsystem 370 may be similar to the asset monitoring subsystem 140, but may monitor, assess, and store the simulated data instead of network traffic 120 data.

As seen in FIG. 3B, a comparison subsystem 321 may compare the captured and indexed activity of the asset monitoring subsystem 140 to the captured and indexed activity of the simulation monitoring subsystem 370. If the comparing reveals that the activity of the asset monitoring subsystem 140 and the simulation monitoring subsystem 370 is statistically similar 322, then there may be increased confidence in the infection being present on asset 331. If the comparing reveals that the activity of the asset monitoring subsystem 140 and the simulation monitoring subsystem 370 is not statistically similar 323, then it may be unlikely that an infection occurred.

If the activities are not statistically similar 323, then this may validate that an infection likely did not occur on the asset 331 and thus a lower confidence score 381 may be presented within a user interface that may be part of, or in communication with, the system 320. This information may help reduce false positives. Furthermore, since it may be likely the malware 310 did not install on the asset 331, then there may be decreased risk 382, see for example U.S. 2012/0143650, posed to an organization and network 330 associated with the asset 331, and information indicating this low risk level may be presented within the user interface.

If the activities are statistically similar 322, then this may validate that an infection occurred and thus an increased confidence score 381 may be presented within the user interface. Furthermore, the confidence in the presence of the infection may increase the risk 382, see for example U.S. 2012/0143650, that the infection poses to the organization and network 330 associated with the asset 331, and information indicating this high risk level may be presented within the user interface. When the activities are statistically similar 322, the system 320 may take the simulated activity 370 and analyze 390, see for example U.S. 2012/0042381, and label 395 the monitored communications as updater, repository, downloader, C&C, etc., thereby generating information which may be used to identify how much data has been exfiltrated from the asset 331 and to where, to allow understanding of malware update frequency, to allow the use of host-based software to retrieve malware updates that were encrypted payloads over the network, and to allow a determination of the infection profile (low and slow, password stealer, information stealer spammer, infecting other internal assets, etc). The labeling may provide context to the purpose of each labeled communications, for example assessing the quantity of data delivered through communications labeled “repository” may indicate how much data theft is occurring and may indicate the threat type as an information stealer.

Reexamination of Indexed Historic, Present, and/or Future Data

Systems and methods may also be provided which may perform reexamination of indexed historic, present, and/or future data to discover precursors to malicious activity as well as present and future activity. This may provide a determination of an origin of the activity that led to the infection. For example, malware may have infected an asset 331 from an ad placed on CNN, a browser exploit, etc. Reexamination may be done by capturing referrer headers, URLs, timestamps, and other attributes. Reexamination may help a user to understand the infector lifecycle, to craft future security software rulesets, to inform acceptable use policies, and/or to reduce the uncertainty of an identified infection.

Discovery and/or recovery of historical infector malware based on future network communications or on future available intelligence based indicators may enable retroactive discovery of stealthy infector malware that may have caused an initial infection on an asset machine. As noted above, suspicious metadata may be stored. The system may also store binaries downloaded in the network for a period of time, and once malicious network traffic is discovered, binaries downloaded by an asset 110 that is suspected to be infected may be meticulously examined to determine the infector malware. This determination may then be provided to a user. Trace data for the infector malware may also be provided to the user. This may allow the discovery of stealthy malware and may provide a technique for thwarting malware detection evasion techniques.

FIG. 4 depicts an analysis process 400 according to an embodiment of the invention. This process 400 may involve the collection and/or analysis of data related to malicious activity of an infection on an asset 110 within a network 100. The timeline 405 in this example shows the time when malicious activity is identified or new threat intelligence based indicators are available 406, the time prior to identification 407, and the time period post identification 408.

During the time prior to identification 407, the discovery/recovery system 410 may utilize the monitoring system 140 described above, which may selectively capture and/or index metadata associated with the activity of endpoints 110 in the network 100. Specifically, historical network communication data may be gathered 421 and analyzed 430. Similarly, historical network file downloads and other suspicious content may be gathered 422 and analyzed 440. Newly identified malicious activity and selective metadata may also be gathered 423.

The analysis of historical network communication data 430 may include analysis and/or re-analysis of each component of historical network communication data to determine new intelligence. As discussed above, network data may be identified as suspicious and may be stored. In many cases, the data may not be immediately analyzed and/or may not be suspicious enough at the time of detection to warrant reporting to a user. However, if an infection is identified, this suspicious data may become more interesting. Analysis and/or reanalysis may be performed to provide deep analysis on data which may have been ignored before identification of infection due to scalability concerns associated with analyzing all collected data. In some cases, brief analysis may be performed upon collection of suspicious data, and more thorough analysis may be triggered by infection identification or by new threat intelligence indicators being available. In other cases, all data (instead of only suspicious data) may be captured by a monitoring system, and analysis of stored data may be triggered by infection identification.

For example a communication attempt may be deemed suspicious enough to capture and index but not suspicious enough at the time of determination to bring to the customer's attention. In this example, there may be 100 indexed but not reported events for an endpoint. At a later date, which may be after detection of an infection in the endpoint, advanced techniques may be applied to examine these 100 events. Examples of analysis and/or reanalysis that may be performed include:

Destination Reputation, for example identifying known malicious or legitimate domain reputations for the destination domain of a communication attempt. See for example U.S. 2012/0042381.

New Destination Classification and Labels, for example receiving passive DNS query information, utilizing the DNS query information to measure statistical features of known malicious and legitimate domain names, and utilizing the statistical features to determine a reputation of a new domain (for example, likely malicious or likely legitimate). See for example U.S. 2012/0042381.

Analysis of headers, for example examining traffic for malformed headers that may have not been considered serious enough to generate an alert.

Analysis of referrers, for example to provide contextual information related to the source of potential malicious communications.

Other, for example the identification of new behavioral patterns or properties based on observed historical activities.

Analyze any newly analyzed files for simulated traffic matches, described in greater detail below with respect to automation discovery.

A user interface 450 may be part of or in communication with the discovery/recovery system 410. The results of the historical network communication data analysis 430 may be presented 451 in the user interface 450. Historical network communication data and highlights on any historical data deemed interesting from retroactive analysis may be presented 451.

The analysis of historical network file downloads and other suspicious content 440 may include retroactive analysis of each historical file and content via static and dynamic analysis.

This may be done even for data that may have been analyzed in the past:

Analyze Source Reputation, for example identifying known malicious or legitimate domain reputations for the domain from which one or more files were downloaded. See for example U.S. 2012/0042381.

Analyze Source Classification & Labels, for example receiving passive DNS query information, utilizing the DNS query information to measure statistical features of known malicious and legitimate domain names, and utilizing the statistical features to determine a reputation of the domain from which one or more files were downloaded (for example, likely malicious or likely legitimate). See for example U.S. 2012/0042381.

Analyze against third party commodity AV detection engines. Identify static structure, for example by searching for well-known malware, identifying trademarks, or finding that a large part of an executable is encrypted.

Identify behavioral traits of file, for example identifying an executable which may start sending email without user interaction or a PDF file which may initiate network communication.

Identify current verdict of file and generate simulated trace report, for example by allowing the file to execute and examining changes to the underlying system. These changes may be analyzed to generate a verdict representing the file's behavior.

The results of the historical network file downloads and other suspicious content analysis 440 may be presented 452 in the user interface 450. Historical file data within the time period before identification time period 406 and highlights on any historical data deemed interesting from retroactive analysis may be presented 452.

An example of historical, present, and/or future analysis may proceed as follows. Infection may occur at 8:00 AM with a dropper that infects an endpoint. The dropper may communicate with a criminal infrastructure and receive a new malware update at 8:30 AM. The update may be a new piece of malware that is sent down in an encrypted payload. That new malware may begin to communicate at 8:35 AM. The system may identify these true malicious communications at 8:35 AM. If all suspicious files downloaded to this endpoint (including the one that caused the infection at 8:00 AM), captured metadata associated with the files, and network communications (which may include communications by the dropper) have been stored, this suspicious data may now be analyzed. The system may retroactively examine the files downloaded prior to the 8:35 AM identification (which may include the dropper at 8:00 AM) and reexamine the suspicious network traffic (which may include the dropper's communications up to the criminal operator). Going forward, other suspicious communications that the infected endpoint makes that may not necessarily be suspicious enough to attribute directly to the infection may now be examined closely. In this example, the identification of a threat at 8:35 AM caused the system to retroactively examine suspicious network traffic and files that may have led to the infection.

When any malicious activity is identified 406, any malicious activity and/or selective metadata newly identified during the present 406 and/or future time period 406 may be captured 423 and presented 453 in the user interface 450. As noted above, this may provide a determination of an origin of the activity that led to the infection and/or help a user to understand the infector lifecycle, to craft future security software rulesets, to inform acceptable use policies, and/or to reduce the uncertainty of an identified infection.

Automation Discovery

Systems and methods may also be provided for determining a degree of automation within suspicious network activity. This may be used to show that malware convictions that were arrived at via other detection techniques exhibit automated behavior (behavior that is machine based instead of user based). This may reduce the uncertainty of convictions.

FIG. 5 depicts a real time analysis process 500 according to an embodiment of the invention. Observed network traffic with either known or low reputation destinations may be collected 510. Analysis of the collected data may be performed 520 which may result in statistical scoring to indicate how automated the observed communications are based on their temporal patterns and attributes. In some embodiments, the analysis may determine the degree of automation via constantly evolving algorithms, an example of which can be described by examining the temporal deltas (time between each) of a series of malware communications and performing statistical analysis to determine that each delta is similar to all of the other deltas. In such an example, the more statistically similar each delta is to the group, the higher the automation score may be. Those of ordinary skill in the art will appreciate that other analysis and/or scoring techniques may be used to identify and/or classify potential automation. The statistical scoring of automation may be based on algorithms 530 built by observing known malware. If statistical scoring indicates a high degree of automation, then the system may indicate a high level of confidence of an infection 540 and thus a high risk factor 550 of the infection and present this information 560 via a user interface.

The probability of maliciousness in network traffic patterns may also be determined. This may allow net new detections via the presence of automated traffic patterns. Data may be gathered as described above with respect to FIG. 2, and this data may be analyzed for the presence of automated behavior using algorithms and low reputation or other information indicative of a malware destination. This may allow the system to detect new threats without any foreknowledge of the threat, and may reduce conviction uncertainty.

FIG. 6 depicts an historical analysis process 600 according to an embodiment of the invention. As described above with respect to FIG. 2, suspicious network traffic may have been captured and indexed. This captured and indexed data may be retrieved 610 for analysis. Analysis of the indexed data may be performed 620, resulting in statistical scoring to indicate how automated the observed communications are. This analysis may use similar techniques to those described above for existing malware detection. The statistical scoring of automation may be based on algorithms 630 built by observing known malware. If statistical scoring indicates a high degree of automation, then the system may indicate a high level of confidence of an infection 640 and thus a high risk factor 650 of the infection and present this information 660 via a user interface.

While various embodiments have been described above, it should be understood that they have been presented by way of example and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope. In fact, after reading the above description, it will be apparent to one skilled in the relevant art(s) how to implement alternative embodiments. Thus, the present embodiments should not be limited by any of the above-described embodiments

In addition, it should be understood that any figures which highlight the functionality and advantages are presented for example purposes only. The disclosed methodology and system are each sufficiently flexible and configurable such that they may be utilized in ways other than that shown.

Although the term “at least one” may often be used in the specification, claims and drawings, the terms “a”, “an”, an, “the”, “said”, etc. also signify “at least one” or “the at least one” in the specification, claims and drawings.

Finally, it is the applicant's intent that only claims that include the express language “means for” or “step for” be interpreted under 35 U.S.C. 112, paragraph 6. Claims that do not expressly include the phrase “means for” or “step for” are not to be interpreted under 35 U.S.C. 112, paragraph 6. 

What is claimed is:
 1. A method comprising: gathering, with a discovery/recovery system comprising a processor in communication with a network, filtered historical network data associated with an asset associated with the network; and analyzing, with the discovery/recovery system, the filtered historical network data to determine whether a subset of the filtered historical network data is associated with a malware infection of the asset.
 2. The method of claim 1, wherein the filtered historical network data comprises historical network communication data.
 3. The method of claim 2, wherein the analyzing comprises identifying a destination and/or source associated with the historical network communication data and identifying a reputation associated with the destination and/or source, measuring a statistical feature of a new destination and/or source associated with the historical network communication data and determining a likely reputation of the new destination and/or source, and/or analyzing a header associated with the historical network communication data, analyzing a referrer associated with the historical network communication data.
 4. The method of claim 3, wherein: the destination and/or source comprises a domain, an IP address, a URL path, and/or a resource; and the new destination and/or source comprises a domain, an IP address, a URL path, and/or a resource.
 5. The method of claim 1, wherein the filtered historical network data comprises an historical network file download.
 6. The method of claim 5, wherein the analyzing comprises identifying a source associated with the historical network file download and identifying a reputation associated with the source, measuring a statistical feature of a new source associated with the historical network file download and determining a likely reputation of the new source, analyzing the historical network file download using a third party commodity, identifying a static structure of the historical network file download, identifying a behavioral trait of the historical network file download, and/or allowing a file associated with the historical network file download to execute and examining a result of the executing.
 7. The method of claim 6, wherein: the source comprises a domain, an IP address, a URL path, and/or a resource; and the new source comprises a domain, an IP address, a URL path, and/or a resource.
 8. The method of claim 1, wherein the filtered historical network communication data comprises suspicious network traffic.
 9. The method of claim 8, further comprising: monitoring, with a monitoring system comprising a processor in communication with the network, network traffic to and/or from an asset associated with the network; assessing, with the monitoring system, the network traffic to determine a destination and/or source for the network traffic and/or content of the network traffic; determining, with the monitoring system, whether the network traffic is suspicious network traffic based on the assessed destination and/or source and/or content; when the network traffic is determined to be suspicious network traffic, capturing, with the monitoring system, metadata associated with the suspicious network traffic and storing the metadata in a database in communication with the processor; and when the network traffic is not determined to be suspicious network traffic, disregarding, with the monitoring system, metadata associated with the network traffic.
 10. The method of claim 9, wherein the monitoring comprises monitoring a transport protocol of the network traffic, monitoring an application protocol of the network traffic, monitoring a destination and/or source of the network traffic, and/or monitoring content of the network traffic.
 11. The method of claim 9, wherein the determining whether the network traffic is suspicious network traffic is based on a low reputation score associated with the destination and/or source for the network traffic, a suspicious DGA cluster associated with the destination and/or source for the network traffic, a suspicious DGA cluster associated with the content of the network traffic, and/or a suspicious content element within the content of the network traffic.
 12. The method of claim 9, further comprising: when the network traffic is determined to be suspicious network traffic, indexing, with the monitoring system, the metadata.
 13. The method of claim 9, wherein the metadata comprises a source port, a destination port, a transport protocol, an application protocol, a time stamp, a duration, a source identifier, a destination identifier, a bytes in count, a bytes out count, a connection success indicator, a connection status, a DNS RR set, HTTP data, a file within the content of the network traffic, the content of the network traffic, and/or a subsequent communication.
 14. The method of claim 9, further comprising: when the network traffic is determined to be suspicious network traffic, sending, with the monitoring system, a report indicating that the network traffic is determined to be suspicious network traffic to a display in communication with the monitoring system.
 15. The method of claim 9, wherein determining whether the network traffic is suspicious network traffic comprises determining that all traffic to and/or from the asset is suspicious network traffic when the asset is an asset with a potential malware infection.
 16. A system comprising: a database; and a discovery/recovery system comprising a processor in communication with a network and in communication with the database, the discovery/recovery system being constructed and arranged to: gather filtered historical network data associated with an asset associated with the network; and analyze the filtered historical network data to determine whether a subset of the filtered historical network data is associated with a malware infection of the asset.
 17. The system of claim 16, wherein the filtered historical network data comprises historical network communication data.
 18. The system of claim 17, wherein the discovery/recovery system is constructed and arranged to analyze the filtered historical network data by identifying a destination and/or source associated with the historical network communication data and identifying a reputation associated with the destination and/or source, measuring a statistical feature of a new destination and/or source associated with the historical network communication data and determining a likely reputation of the new destination and/or source, and/or analyzing a header associated with the historical network communication data, analyzing a referrer associated with the historical network communication data.
 19. The system of claim 18, wherein: the destination and/or source comprises a domain, an IP address, a URL path, and/or a resource; and the new destination and/or source comprises a domain, an IP address, a URL path, and/or a resource.
 20. The system of claim 16, wherein the filtered historical network data comprises an historical network file download.
 21. The system of claim 20, wherein the discovery/recovery system is constructed and arranged to analyze the filtered historical network data by identifying a source associated with the historical network file download and identifying a reputation associated with the source, measuring a statistical feature of a new source associated with the historical network file download and determining a likely reputation of the new source, analyzing the historical network file download using a third party commodity, identifying a static structure of the historical network file download, identifying a behavioral trait of the historical network file download, and/or allowing a file associated with the historical network file download to execute and examining a result of the executing.
 22. The system of claim 21, wherein: the destination comprises a domain, an IP address, a URL path, and/or a resource; and the new destination comprises a domain, an IP address, a URL path, and/or a resource.
 23. The system of claim 16, wherein the filtered historical network communication data comprises suspicious network traffic.
 24. The system of claim 23, further comprising: a monitoring system comprising a processor in communication with the network and in communication with the database, the monitoring system being constructed and arranged to: monitor network traffic to and/or from an asset associated with the network; assess the network traffic to determine a destination and/or source for the network traffic and/or content of the network traffic; determine whether the network traffic is suspicious network traffic based on the assessed destination and/or source and/or content; when the network traffic is determined to be suspicious network traffic, capture metadata associated with the suspicious network traffic and store the metadata in the database; and when the network traffic is not determined to be suspicious network traffic, disregard metadata associated with the network traffic.
 25. The system of claim 24, wherein the monitoring comprises monitoring a transport protocol of the network traffic, monitoring an application protocol of the network traffic, monitoring a destination of the network traffic, and/or monitoring content of the network traffic.
 26. The system of claim 24, wherein the determining whether the network traffic is suspicious network traffic is based on a low reputation score associated with the destination and/or source for the network traffic, a suspicious DGA cluster associated with the destination and/or source for the network traffic, a suspicious DGA cluster associated with the content of the network traffic, and/or a suspicious content element within the content of the network traffic.
 27. The system of claim 24, wherein the monitoring system is further constructed and arranged to: when the network traffic is determined to be suspicious network traffic, index the metadata.
 28. The system of claim 24, wherein the metadata comprises a source port, a des+ination port, a transport protocol, an application protocol, a time stamp, a duration, a source identifier, a destination identifier, a bytes in count, a bytes out count, a connection success indicator, a connection status, a DNS RR set, HTTP data, a file within the content of the network traffic, the content of the network traffic, and/or a subsequent communication.
 29. The system of claim 24, wherein the monitoring system is further constructed and arranged to: when the network traffic is determined to be suspicious network traffic, send a report indicating that the network traffic is determined to be suspicious network traffic to a display in communication with the monitoring system.
 30. The system of claim 24, wherein the monitoring system is constructed and arranged to determine whether the network traffic is suspicious network traffic with a method comprising determining that all traffic to and/or from the asset is suspicious network traffic when the asset is an asset with a potential malware infection. 